Should you learn Ruby depends what you want to use it for.
If you want to build websites that does unique things (things you can't find a Wordpress Plugin for). And if your main constraint is money (which equials programmer hours), so it has to be done by one person or a small team in a limited amount of time, then it just so happens ​that Rails which is a framework written & built upon with Ruby is the best tool for the job. It can do many other things well, but for this use case I'll argue it is the very best.
The other places where Ruby really shines are making scripts for text processing & setting up of servers.
Double bonus, Ruby is fun to learn & work with. And there are tons of video tutorials online.
This has been my favorite
If you don't have the budget for it I have heard really good things about this guy's free book